Biomedical subjects

S Higashi

Publications and source records attributed to S Higashi.

At least 19 recordsLinked to original sources

PubMed2006

Nucleotide diversity of Japanese isolates of infectious hematopoietic necrosis virus (IHNV) based on the glycoprotein gene.

Infectious hematopoietic necrosis virus (IHNV), a member of the genus Novirhabdovirus, causes a highly lethal disease of salmonid fish. In the present study, G gene nucleotide sequences of 9 Japanese IHNV isolates obtained from 1971 to 1996 were analyzed to evaluate the genetic diversity and compared with IHNV isolates from North America and Europe. A radial phylogenetic tree revealed 5 major clusters including 3 genogroups (U, M and L) for North American isolates and 1 genogroup for European isolates. Five Japanese isolates from 1971 to 1982 appeared in the cluster for genogroup U, while the remaining Japanese isolates from 1980 to 1996 formed a new genogroup, JRt (Japanese rainbow trout). Maximum nucleotide diversity among the Japanese isolates was 4.5%, which was greater than that within the North American isolates (3.6%), and the degree of nucleotide diversity within Japanese isolates was increased by inclusion of the genogroup JRt isolates. It was concluded that Japanese isolates shared a common source with the genogroup U of the North American isolates and that there were large divergences between Japanese isolates before and after the 1980s.

Animals↗

PubMed2006

Efficacy and safety of nurse-administered propofol sedation during emergency upper endoscopy for gastrointestinal bleeding: a prospective study.

BACKGROUND AND STUDY AIMS: Recent studies have documented the safety of propofol sedation for endoscopic procedures, but many endoscopists are reluctant to use propofol for high-risk patients because of adverse effects. The aim of this study was to demonstrate the safety and efficacy of nurse-administered propofol sedation during emergency upper endoscopy for patients with gastrointestinal bleeding. PATIENTS AND METHODS: Over a period of 18 months, 120 patients suffering from acute upper gastrointestinal bleeding received propofol sedation administered by a registered nurse. Among these, 15 patients were classified into American Society of Anesthesiologists (ASA) class IV, 84 were ASA class III, and 21 were ASA class II. Patients without gastrointestinal bleeding, who also received propofol during the same period and were matched for age, gender, and ASA class, served as controls. RESULTS: Endoscopic hemostasis was achieved in 98.3 % of patients, and 97.5 % were satisfied with the procedure. In patients with gastrointestinal bleeding, the rates of hypotension (systolic blood pressure < 90 mmHg) and hypoxemia (peripheral oxygen saturation < 90 %) were 8.3 % and 6.7 % respectively, values higher than those in the control group. However, neither mask ventilation nor endotracheal intubation was necessary. Although two patients with gastrointestinal bleeding developed pneumonia, most likely due to aspiration during the procedure, they recovered within 5 days of treatment. There were no sedation-associated severe complications or mortalities. CONCLUSION: Using a strict protocol designed to protect the patient's airway and cardiovascular function, nurse-administered propofol sedation during emergency upper gastrointestinal endoscopy is safe and appropriate in cases of acute gastrointestinal bleeding.

Acute Disease↗

PubMed2006

Propofol sedation during endoscopic procedures: safe and effective administration by registered nurses supervised by endoscopists.

BACKGROUND AND STUDY AIMS: Propofol has several attractive properties, including a rapid onset of action and rapid recovery. However, the administration of propofol sedation in the absence of anesthesiologists remains controversial. This report describes the safety profile of propofol sedation for endoscopy when administered by registered nurses under the supervision of endoscopists. PATIENTS AND METHODS: The study was conducted in the endoscopic center of a Japanese private hospital. With assistance from an anesthesiologist, a protocol for administration of propofol by registered nurses was developed. Over the past 6 years, 27,500 patients received nurse-administered propofol sedation. The safety and patient satisfaction with this sedation procedure were evaluated. RESULTS: Among the participating patients, 6.7% developed hypoxemia (Sp(O2) < 90%); 6.2% required oxygen administration via a nasal cannula. Severe hypoxemia (Sp(O2) < 85%) occurred in 121 patients (0.62%) during upper gastrointestinal endoscopy and 20 patients (0.25%) during colonoscopy, but neither mask ventilation nor endotracheal intubation was necessary. A decline in blood pressure (systolic blood pressure < 90 mm Hg) was seen in 3.5% of the colonoscopy patients and 1.2% of the upper endoscopy patients. However, hypotension was corrected immediately using an intravenous saline solution. Patients who received propofol sedation expressed overall satisfaction on a 10-point visual analogue scale (with an average of 9.4 points). Among patients who had previously received a combination of midazolam and pethidine for colonoscopy, 85% preferred propofol sedation. The mean time from the end of the procedure to full recovery was 14.6 min. CONCLUSIONS: Administration of propofol by registered nurses under the supervision of endoscopists was safe, and resulted in high rates of patient satisfaction.

Adolescent↗

PubMed2005

Significance of SAA1.3 allele genotype in Japanese patients with amyloidosis secondary to rheumatoid arthritis.

OBJECTIVE: To clarify the clinical significance of the SAA1.3 allele in the development and outcome of AA amyloidosis in Japanese patients with rheumatoid arthritis (RA). METHODS: One hundred and twenty RA patients (60 alive and 60 dead) fulfilling the 1987 ACR criteria and 62 RA patients with biopsy-confirmed amyloid A (AA) amyloidosis (36 alive and 26 dead) were enrolled. The SAA1 genotypes were determined by PCR-based restriction fragment length polymorphism. To predict the clinical outcome of AA amyloidosis, we investigated characteristics and survival, focusing on the SAA1.3 allele retrospectively. RESULTS: The SAA1.3 allele genotype was not only a risk factor for the association of AA amyloidosis but also a poor prognostic factor for the development of AA amyloidosis (P=0.015). Both the association of AA amyloidosis arising early in the RA disease course and symptomatic variety and severity were found in amyloidotic patients with the SAA1.3 allele. The presenting factors adversely influenced were age (P=0.001), lowered serum albumin (P=0.001) and creatinine concentration (P=2.14 x 10(-5)). Renal involvement was associated with poor survival in patients with AA amyloidosis (P=0.011) and the presence of cardiac involvement was likely to be a risk factor for survival (P=0.062). The rate of the causes of death in respect to the category of infection, gastrointestinal diseases, and renal failure was higher in patients with AA amyloidosis than in those without amyloidosis, gastrointestinal diseases and renal failure. Cyclophosphamide was found to be superior to methotrexate in the management of RA patients with AA amyloidosis. CONCLUSION: Our data support the fact that homozygosity for the SAA1.3 allele is a univariate predictor of survival in addition to a risk factor for the association of AA amyloidosis adversely influencing the outcome in Japanese RA patients. Renal involvement is a pivotal clinical manifestation in the development of AA amyloidosis, as is likely to be cardiac involvement in AA amyloidosis secondary to RA.

Amyloidosis↗

PubMed2002

A comparison of alfacalcidol and menatetrenone for the treatment of bone loss in an ovariectomized rat model of osteoporosis.

We conducted this study to evaluate the characteristic effects of alfacalcidol (ALF) and menatetrenone (VK) in preventing bone loss using an ovariectomized rat model of osteoporosis. Bilateral ovariectomy (OVX) or sham operation was performed on 10-month-old female Wistar rats. OVX caused a significant decrease in the bone mass and the mechanical strength of the lumbar vertebra as well as the femur 6 months after surgery. VK treatment (30 mg/kg, food intake) required a 6-month period to prevent the bone loss induced by estrogen deficiency, whereas ALF (0.1 or 0.2 mg/kg, p.o.) increased the bone mass and the mechanical strength of the lumbar vertebra as well as the femur in a 3-month treatment period, far above the level in the sham-operated rats. Neither ALF or VK caused hypercalcemia, despite administration for as long as 6 months. By doing a micro-CT analysis of the vertebral trabecular microstructure, it was revealed that ALF treatment increased the interconnections and the plate-like structures and that VK significantly increased the trabecular number. It was also indicated that the increase in spinal strength by ALF treatment was closely associated with improvement of the microstructure, but not VK. The results of histomorphometric analysis showed that ALF caused a significant suppression of bone resorption yet maintained formation in the endocortical perimeter, and also stimulated bone formation in the periosteal perimeter, thereby causing an increase in cortical area. No marked effect of VK on histomorphometric parameters was observed, whereas VK as well as ALF maintained the material strength at femoral midshaft of the normal level, suggesting that VK affected bone quality and thereby prevented the decrease in mechanical strength of femur caused by OVX. In conclusion, it was demonstrated that the two drugs, ALF and VK, differed markedly in their potency and mechanisms for improving bone strength. These results have important implications in understanding the characteristic actions of vitamin K and active vitamin D on bone metabolism.

Animals↗

PubMed2002

Prenatal development of neural excitation in rat thalamocortical projections studied by optical recording.

To elucidate the formation of early thalamocortical synapses we recorded optical images with voltage-sensitive dyes from the cerebral cortex of prenatal rats by selective thalamic stimulation of thalamocortical slice preparations. At embryonic day (E) 17, thalamic stimulation elicited excitation that rapidly propagated through the internal capsule to the cortex. These responses lasted less than 15 ms, and were not affected by the application of glutamate receptor antagonists, suggesting that they might reflect presynaptic fiber responses. At E18, long-lasting (more than 300 ms) responses appeared in the internal capsule and in subplate. By E19, long-lasting responses increased in the cortical subplate. By E21, shortly before birth, the deep cortical layers were also activated in addition to the subplate. These long-lasting responses seen in the internal capsule and subplate were blocked by the antagonist perfusion, but the first spike-like responses still remained. The laminar location of the responses was confirmed in the same slices by Nissl staining and subplate cells were labeled by birthdating with bromodeoxyuridine at E13. Our results demonstrate that there is a few days delay between the arrival of thalamocortical axons at the subplate at E16 and the appearance of functional thalamocortical synaptic transmission at E19. Since thalamocortical connections are already functional within the subplate and in the deep cortical plate at embryonic ages, prenatal thalamocortical synaptic connections could influence cortical circuit formation before birth.

Action Potentials↗

PubMed2002

[A case of acute erythroblastic anemia due to infection with human parvovirus B19 after coronary artery bypass grafting].

A 37-year-old male developed reticulocytopenia and leukopenia with fever from the 11th patient day after coronary artery bypass grafting. Bone-marrow puncture revealed a marked decrease of erythroblasts and appearance of giant proerythroblasts. Thus, infection with human parvovirus B 19 (HPV-B 19) was suspected. At the onset of the disease, only IgM antibody was positive, but later IgG antibody also turned positive, and DNA of HPV-B19 was detected by polymerase chain reaction (PCR) from the bone marrow specimen of the patient. Then the patient was diagnosed with acute erythroblastic anemia due to infection with HPV-B19. In this case, DNA of HPV-B19 was detected by PCR from a fibrin sealant used during operation. The fibrin sealant was found to be the source of infection. Fibrin sealants are used widely in the domain of surgery. Therefore, we should perform screening of plasma and make examination of the sealants, while paying attention to infections with HPV-B 19 in the future.

Adult↗

PubMed2002

[A case of atypical aortic coarctation with mitral and aortic regurgitation and ascending aortic dilatation].

A 67-year-old female presented with dyspnea on exertion as a chief complaint. Diagnosed as having severe mitral regurgitation, aortic regurgitation, dilatation of the ascending aorta and atypical coarctation due to aortitis syndrome, she underwent mitral valve replacement, aortic valve replacement, ascending aorta and hemiarch replacement and ascending aorta-abdominal aorta extraanatomical bypass in one stage. Pathologically, typical findings of aortitis syndrome were not observed in the wall of the ascending aorta and aortic valve, but cystic medionecrosis was noted in the wall of the ascending aorta. Follow-up observations are needed for the remaining aortic wall.

Aged↗

PubMed2002

[Experience with pyoktanin lavage for mediastinitis and prosthetic graft infection following thoracic aortic surgery].

Pyoktanin, a triphenylmethane dye, is known to have a potent bactericidal activity against Gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). We used pyoktanin for irrigating wounds in 2 cases of mediastinitis and prosthetic graft infection following thoracic aortic surgery. Case 1 is mediastinitis and prosthetic graft infection due to Staphylococcus epidermidis following Cabrol procedure. After irrigating the anterior mediastinum with 0.1% pyoktanin solution twice a day for 8 days, omental transposition was performed, which let to cure of the infection. Case 2 is mediastinitis due to methicillin-resistant Staphylococcus epidermidis following ascending aortic and aortic arch replacement for acute type A aortic dissection. After irrigating the wound with 0.1% pyoktanin solution twice a day for 14 days, the wound was closed primarily, which resulted in cure of the infection of the wound. Using pyoktanin at low concentrations for irrigating wound for a short period of time is considered permissible and effective for mediastinitis and prosthetic graft infection due to Gram-positive bacteria including MRSA.

Anti-Infective Agents, Local↗

PubMed2002

[Acute aortic regurgitation due to localized aortic dissection adjacent to the commissure of the aortic valve].

A 78-year-old male with a sudden loss of consciousness and chest pain was transferred to our hospital. He presented heart failure due to severe aortic regurgitation. Cardiac ultrasonography and computed tomography (CT) scanning did not lead to an established diagnosis of acute aortic dissection. Aortic valve replacement was performed 24 days after the onset of the disease. The surgical findings showed prolapse of the aortic valve due to localized dissection adjacent to the commissure of the aortic valve.

Acute Disease↗

PubMed2001

Cloning and expression of a down-regulated gene (TrEnodDR1) of white clover responded by the nod genes derived from Rhizobium leguminosarum bv. trifolii strain 4S.

The nodulation genes of Rhizobium leguminosarum bv. trifolii 4S (strain 4S) were cloned into cosmid vector pLAFR1 named pC4S8 which was contained nodNMLFEDABCIJ and a part of nodT as an insert. The pC4S8 was transferred to strain H1, Sym plasmid (pRt4Sa) cured strain of strain 4S, and isolated as Tc resistant and nodulation restored mutant, strain H1(pC4S8). During infection process of this strain, visible symbiotic features, such as root hair curling (Hac), root hair deformation (Had) and infection thread formation (Inf) were also restored. The nodule forming ability of strain H1(pC4S8) was increased 3-4 times in nodule number than that of strain 4S. Then, to investigate the effect of Rhizobium nod genes on the host plant (Trifolium repens L.) gene expression, cDNAs which were responded to the inoculation of rhizobia were differentially screened based on the presence or absence of nod genes treated with strains H1(pC4S8) or H1, respectively. The cDNA, TrEnodDR1 (Trifolium repens early nodulin down regulation 1) gene was isolated from cDNA library prepared from white clover seedlings treated with nod- strain H1, but didn't exhibit in nod+ treated cDNA library, as a down-regulated gene. Expression analysis of TrEnodDR1 was performed in various tissues of white clover, it is suppressed in root nodule and also strongly suppressed by the inoculation of rhizobia in the seedlings. It is discussed that TrEnodDR1 gene is suppressed when the white clover comes into symbiosis with rhizobia.

Amino Acid Sequence↗

PubMed2001

Factor VIIa modified in the 170 loop shows enhanced catalytic activity but does not change the zymogen-like property.

Factor VIIa (VIIa) is an unusual trypsin-type serine proteinase that appears to exist in an equilibrium between minor active and dominant zymogen-like inactive conformational states. The binding of tissue factor to VIIa is assumed to shift the equilibrium into the active state. The proteinase domain of VIIa contains a unique structure: a loop formed by a disulfide bond between Cys310 and Cys329, which is five residues longer than those of other trypsin types. To examine the functional role of the loop region, we prepared two mutants of VIIa. One of the mutants, named VII-11, had five extra corresponding residues 316-320 of VII deleted. The other mutant, VII-31, had all of the residues in its loop replaced with those of trypsin. Functional analysis of the two mutants showed that VIIa-11 (Kd = 41 nm) and VIIa-31 (Kd = 160 nm) had lower affinities for soluble tissue factor as compared with the wild-type VIIa (Kd = 11 nm). The magnitude of tissue factor-mediated acceleration of amidolytic activities of VIIa-11 (7-fold) and that of VIIa-31 (2-fold) were also smaller than that of wild-type VIIa (30-fold). In the absence of tissue factor, VIIa-31 but not VIIa-11 showed enhanced activity; the catalytic efficiencies of VIIa-31 toward various chromogenic substrates were 2-18-fold greater than those of the wild-type VIIa. Susceptibility of the alpha-amino group of Ile-153 of VIIa-31 to carbamylation was almost the same as that of wild-type VIIa, suggesting that VIIa-31 as well as wild-type VIIa exist predominantly in the zymogen-like state. Therefore, the tested modifications in the loop region had adverse effects on affinity for tissue factor, disturbed the tissue factor-induced conformational transition, and changed the catalytic efficiency of VIIa, but they did not affect the equilibrium between active and zymogen-like conformational states.

Amino Acid Sequence↗

PubMed2001

Geranylgeranylacetone induces antiviral gene expression in human hepatoma cells.

Geranylgeranylacetone (GGA), an isoprenoid compound, is used clinically as an anti-ulcer drug. Since some isoprenoids including retinoids have anti-tumor and anti-viral activities in a variety of cell types, we investigated whether GGA could induce anti-viral proteins in human hepatoma cells. The HuH-7 and HepG2 cells were treated with GGA, and expression of anti-viral proteins such as 2'5'-oligoadenylate synthetase (2'5'-OAS) and double-stranded RNA-dependent protein kinase (PKR) in these cells was analyzed. GGA stimulated 2'5'-OAS and PKR gene expression at the transcriptional level through the formation of interferon-stimulated gene factor 3 (ISGF3), which regulates both gene transcription. By Western blotting, GGA induced expression of signal transducers and activators of transcription 1, 2 (STAT1, STAT2) and p48 proteins, components of ISGF3, together with the phosphorylation of STAT1. These results suggest that GGA acts as a potent inducer of anti-viral gene expression by stimulating the ISGF3 formation in human hepatoma cells.

2',5'-Oligoadenylate Synthetase↗

PubMed2001

Saccular aneurysm in the left main coronary artery.

The patient was a 70-year-old male with a chief complaint of chest pain. Coronary angiography revealed a saccular aneurysm of 11 mm in diameter at the furcation of the left main coronary artery. Triple vessel disease was also seen. At surgery, it was judged that the risk to rupture of the aneurysm was high because the aneurysmal wall was very thin. Therefore, the blood flow into the aneurysm was blocked, and coronary artery bypass grafting was performed. In a pathological study on the aneurysmal wall, no atherosclerotic and no inflammatory changes were found, but acidic mucopolysaccharides were detected in the tunica media. Coronary aneurysms with coronary stenosis in the elderly have been reported to be arteriosclerotic without exception. Here we present this rare case of a left main coronary artery aneurysm with coronary stenosis in an old-aged patient, considered to be due to metabolic abnormalities in the smooth muscle cells.

Aged↗

PubMed2001

Failure of ureteric bud invasion: a new model of renal agenesis in mice.

FUBI (failure of ureteric bud invasion) is a highly inbred strain of mouse with a high spontaneous incidence of uni- or bilateral renal agenesis (60%). Bilateral renal agenesis is lethal within 2 days after birth. The primary defect of FUBI is failure of the ureteric bud to penetrate into the metanephric mesenchyme at around embryonic day 11, resulting in apoptosis of metanephric cells and leading to renal agenesis on the affected side. The metanephros seemed to be normal because co-culturing of the FUBI metanephros with homologous spinal cord induced differentiation of the rudiment, but co-culturing with the homologous ureteric bud frequently did not. Genetic analysis revealed that more than two genes were involved in this malformation and we mapped one of the modifier loci, fubi1, on chromosome 2, at approximately 65 cM from the centromere. In this region, there are two possible candidate genes, Wilms' tumor 1 and formin, that play important roles in kidney development. Some of formin mutants shared a similar phenotype with FUBI; however, there was no difference in the expression of formin in embryonic kidneys between FUBI and control NFS/N mice. Studies of fubi1 congenic mice indicated that interaction of two or more loci is essential for the FUBI phenotype.

Animals↗

PubMed2001

Sinus node function after mitral valve surgery using the superior septal approach.

UNLABELLED: BACKGROUND; Sinus node function after the superior septal approach (SSA) in mitral valve surgery is controversial. We assessed sinus node function after this approach based on electrophysiological examinations and electrocardiographic change. METHODS: Forty-six patients underwent successful mitral valve surgery via the SSA. Preoperatively, 25 patients were in atrial fibrillation (AF), 20 were in normal sinus rhythm (SR), and 1 patient was paced. Thirteen patients who demonstrated no sinus node dysfunction preoperatively underwent postoperative electrophysiological studies. Peripostoperative cardiac rhythm was monitored using a portable four-lead electrocardiograph, and late cardiac rhythm was examined using standard 12-lead electrocardiography in the outpatient clinic. RESULTS: Twelve of 20 patients with preoperative SR experienced early postoperative supraventricular arrhythmias, but all spontaneously recovered SR. Electrophysiological studies revealed a basic cycle length of 767 +/- 74 ms, sinoatrial conduction time of 72 +/- 34 ms, sinus node recovery time of 1,119 +/- 139 ms, and corrected sinus node recovery time of 349 +/- 114 ms, thus demonstrating a lack of sinus node dysfunction. During the postoperative period (34 +/- 24 months), 2 of the 20 patients with preoperative SR developed persistent AF, and 3 of the 25 patients with preoperative AF achieved normal SR. CONCLUSIONS: The SSA does not appear to cause longterm adverse effects on sinus node function, although temporary effects may occur.

Adult↗

PubMed2001

A long-term follow-up analysis of serial core promoter and precore sequences in Japanese patients chronically infected by hepatitis B virus.

To investigate the association of hepatitis B virus (HBV) with core promoter mutation (T1762A1764) or precore mutation (A1896) with the clinical course of illness, we analyzed serial core promoter and precore sequences in 22 patients with HBV-associated chronic liver disease who were followed for 12+/-4 years (mean +/- SD). Sixteen of 22 patients were positive for HBeAg at baseline, and 15 of the 16 patients seroconverted to anti-HBe during the observation period. T1762A1764 mutation was detected in 16 of 22 patients, including 11 patients positive for HBeAg, at baseline. During the follow-up period, A1896 mutation emerged in 7 of 16 patients who had the wild-type HBV or only the T1762A1764 mutation at baseline. Sustained remission of hepatitis correlated with the low level of viremia, but did not with type of mutations. These results indicate that HBV with T1762A1764 mutation tends to precede A1896 mutation during the course of infection in Japanese patients with chronic liver disease.

Adult↗

PubMed2001

Angiosarcoma of the scalp: absence of vascular endothelial cadherin in primary and metastatic lesions.

A 73-year-old man with angiosarcoma of the scalp died about 1 year after disease onset, despite systemic and topical administration of recombinant interleukin-2. Histopathology showed typical changes of endothelial cells with very sparse lymphocytic infiltration into the tumour. An autopsy revealed that the primary site penetrated cranial bone and invaded vertically into the subarachnoid space. Multiple metastases to lung, chest wall, vertebrae and ribs were also found. On immunofluorescence staining, the expression of vascular endothelial cadherin, which is present in normal endothelium, was absent from both primary and metastatic sites. This may have promoted local invasion and metastasis.

Aged↗